In the absence of any reason offered by the man himself, speculation is rife.
There are mutterings about impressing his New Labour bosses with a squeaky- clean image. Hardly likely, as Education and Employment Secretary David Blunkett sports the hirsute style.
But less kind colleagues wondered if it was just that Dr Tate's greying beard failed to match his darker hair? Or is he a victim of the male menopause? But many think he looks younger. We learn that the new look is permanent, so watch this space as his press office is charged with the task of getting a whole new set of mug--shots taken. Dr Tate declined to discuss the matter.